Northwestern quarterback Kain Colter speaks at a press conference as Leo W. Gerard, President of the National Steelworkers union, listens on Jan. 28 2014 at The Hyatt Regency Hotel in Chicago. Citing what they deem as the NCAA's abdication of responsibility to protect athletes from injury, the College Athletes Association (CAPA) announced the creation of the new labor organization to represent college football and basketball players. (Photo by David Banks/Getty Images)

In a unanimous decision, the NLRB said the prospect of having both union and nonunion teams could lead to different standards at different schools — from the amount of money players receive to the amount of time they can practice — and create competitive imbalances throughout college sports.

The ruling dismissed a March 2014 decision by a regional NLRB director in Chicago who said football players with scholarships are effectively school employees and entitled to organize. But Monday’s decision did not directly address the question of whether the players are employees.

“Although we do not decide the issue here, we acknowledge that whether such individuals meet the board’s test for employee status is a question that does not have an obvious answer,” the board said.

The labor dispute goes to the heart of American college sports, where universities and conferences reap billions of dollars, mostly through broadcast contracts, by relying on amateurs who are not paid. In other countries, college sports are small-time club affairs, while elite youth athletes often turn pro as teens.

At the heart of the ruling, the board said, is the NLRB’s jurisdiction, which extends only to private schools like Northwestern, the sole private institution in the Big Ten. The board repeatedly cited the need for standardization of rules and policies in sports and said that giving the green light to just one team to collectively bargain would disrupt that uniformity.

“Processing a petition for the scholarship players at this single institution under the circumstances presented here would not promote stability in labor relations,” the ruling said.

NLRB rules do not offer the losing side, in this case the pro-union forces, an option to appeal the board’s decision. The board did leave the door open to taking up the college sports unionization issue again if it involves other schools or if conditions change for Northwestern football players.

Northwestern became the focal point of the labor fight in January 2014, when a handful of football players called the NCAA a “dictatorship” and announced plans to form the first U.S. labor union for college athletes. Quarterback Kain Colter appeared at a news conference for the College Athletes Players Association, flanked by leaders of the United Steelworkers union, which lent its organizing expertise and presumably helped bankroll the union drive.

Three months later, regional NLRB Director Peter Sung Ohr issued a stunning decision, saying Northwestern football players who receive scholarships fit the definition of employees under federal law and therefore should be able to unionize. A month later, football players cast secret ballots on whether to unionize. Those ballots were sealed during the appeal and will now be destroyed.

Colter said he was disappointed with the ruling but did not regard it as a “complete loss.” Rather, he said, the NLRB simply “punted the ball down the field,” preserving the possibility that the effort could be revived in the future.

He said he thinks the push to unionize has already made conditions better for student athletes.

University spokesman Alan K. Cubbage thanked the players for “bringing national attention to these important issues” but said collective bargaining is “not the appropriate methods to address the concerns.”

Cubbage said the university would work with the athletes to address questions about the long-term health impact of intercollegiate sports, including providing additional academic aid and other opportunities.

While NLRB decisions are sometimes split, the three Democrats and two Republicans on the board all agreed.

Under U.S. law, an employee is regarded as someone who, among other things, receives compensation for a service and is under the direct control of managers. In Northwestern’s case, Ohr concluded coaches are equivalent to business managers and scholarships are a form of pay.

The ruling was welcome news for the NCAA, the dominant umbrella organization for U.S. college athletics. The NCAA has been under increasing scrutiny over its amateurism rules and has been in court fighting lawsuits from former athletes over everything from head injuries to revenue earned based on the use of their likenesses in video games.

The NCAA recently cleared the way for the five biggest conferences, including the Big Ten, to add player stipends to help athletes defray some of their expenses. Southeastern Conference schools, for example, will give some athletes $3,000 to $5,500 each on top of a scholarship that pays for tuition, room, board and books.

Northwestern, the Big Ten and the NCAA all argued against the unionization effort, saying that lumping college athletes into the same category as factory workers would transform amateur athletics for the worse. At one point, Northwestern administrators sent a document to players outlining potential pitfalls, noting that player strikes could lead to the spectacle of replacement players.

The specific goals of the players association, or CAPA, include guaranteeing coverage of sports-related medical expenses for current and former players, reducing head injuries.